Expensive lessons from Warrnambool Telstra exchange fire

TELSTRA has vowed to improve regional telephone exchanges around Australia following an extensive investigation into last year’s devastating Warrnambool fire which cut services to more than 100,000 people.

However, after 100 days of investigations there still has not been a clear cause of the November 22 blaze which started in a maintenance control room at the 1950s building in Koroit Street and disabled vital equipment and cables.

It took more than $10 million to rebuild the exchange and restore services, with work still continuing.

The national telco has diversified its network links rather than concentrate all services through a single exchange, as was the case before the fire, to prevent another total regional outage.

Telstra yesterday released a summary of its 700-page report which will be given to the federal Department of Broadband, Communications and Digital Economy which is expected to deliver its own report mid-year.

The Victorian Govern-ment also recently released its submission to the federal department detailing the social and economic costs of the outage and opportunities for reform.

Telstra’s report contains 22 recommendations for better fire protection, alarm systems, maintenance and back-up at exchanges, along with new disaster recovery plans and more emergency support equipment.

“We will put in place a range of physical, process and disaster recovery improvements to minimise the chance of something like this happening again,” Telstra’s chief operations officer Brendon Riley said.

“We can never completely protect against this type of incident, but we can learn from it to improve the resilience and robustness of our network across Australia for our customers.”

There were four separate investigations — two by the Country Fire Authority, one by Telstra and another by an independent fire investigator.

They found intense heat, smoke, soot and contaminants disabled equipment and cables.

There was no insulation around cables into the room where the fire started. This could have mitigated smoke penetration into other parts of the building.

“Multiple investigations have found the root cause was most probably an electrical malfunction,” the report said.

“Due to the extent of the damage it has not been possible to identify a single ignition source that led to the fire starting.

“The probable location of the source was either in the ceiling of the maintenance control room or the maintenance control room itself.”

Alarm systems and control system logs were found to have operated correctly and alerted staff in Telstra’s global control centre in Melbourne immediately.

“Early that morning I got a call (that) it was a very, very serious fire,” Mr Riley said.

“I then called our chief executive.”

Report author David Piltz, a 40-year Telstra veteran, said the alarm and monitoring systems showed within minutes it was a serious disruption.

“I’ve been through our records and we haven’t had an exchange fire like this since 1961 in Canberra,” he said.

“It damaged critical equipment and cable trays which meant a total rebuild.

“The scale of the rebuilding effort was world-class. I don’t think any restoration like this has been seen before in Australia or anywhere else in the world.”

Electricity supply emergency shutoff systems in regional exchanges will also be modified because of the Warrnambool fire.

When they shut down mains power, a back-up generator in a separate locked enclosure was triggered into action, and when that was turned off there was still electricity supply from banks of batteries.

The continuing electrical power kept airconditioners running, which fanned the fire’s intensity.

Mr Piltz said new easily-accessible shutoff switches, fire alarms and sensors plus ceiling and wall cavity insulation would be installed.

Main telecommunication cables have also been separated to reduce the likelihood of total outage.

“Everywhere we can things have been duplicated to minimise the risk,” he said.

Telstra's director of network engineering David Plitz (left) and chief operating officer Brendon Riley with copies of the company's report into last November's exchange fire, in the room where the fire is believed to have started.